A wake-up call to save the common otters
Israel’s Common Otter (Lutra) population is on the brink of extinction; reports Shmulik Yedvab, head of the Society for the Protection of Nature in Israel Mammal Department.
Yedvab’s alarming conclusion is based on the recently completed 2015 survey of local Otters’ habitats. The report was carried out by SPNI and Dr. Amit Dolev, an ecologist from Israel Nature and Park Authority.
The report reveals the continuance of the worrying trend of otters being seen in 20% fewer places over the last 15 years.
A friendly, playful swimmer, found in wetland habitats including rivers, reservoirs and fishponds, the otter’s presence, or lack thereof, is a key indicator of the eco-system’s wellbeing and diversity.
About Israel’s Otters
Until the beginning of the 20th century, otters were commonly spotted in all Israel’s coastal streams, from the Lebanese border down to Sorek creek (Nahal Sorek) and along the Jordan river, starting at its northern sources until the Dead Sea, including the Hula valley and the Kinneret. The Otter is a predator feeding on crustaceans, amphibians and other small animals and is often mistaken for a Coypu (Myocaster coypus) which resembles it a little but is actually an invasive species that was brought to Israel from South America in an attempt to develop a local fur industry.
The three valleys of Beit She’an, Harod and Jezreel served as an ecological corridor, linking between the otters in the Jordan basin and the population around the coastal plain.
Though protected under the Law for the protection of wild animals since 1964, over the last decades the otter population has suffered from a dramatic deterioration in numbers and distribution, leading it to be classified as critically endangered.
A Population in Decline
During the 2015 survey a total of 119 sites were sampled, in addition to 20 marked habitats located at the Hula nature reserve. In each site we looked for evidence of tracks and droppings along river banks and below bridges as well as taking into account public reports of sightings. The results resemble those of the previous year with some additional emphasis: a small but steady population evident in the Hula valley, the Jordan River sources, the northern Kinneret and the Hula nature reserve. Elsewhere evidence of otters was scarce, and the previously stable otter population at the Bental reservoir in the northern Golan Heights has completely disappeared.
1. Distribution surveys
The surveys are performed since the year 2000 and include locating animal droppings, which the otters use to mark their territory. The search around rivers and streams is mostly under bridges where the otters have been known to leave such traces.
Reports on live or dead otters spotted by SPNI field staff, the Israel Nature and Park Authority staff and the general public, are collected throughout the year and documented at a mammal data center. DNA tissue samples are collected from dead otters for analysis by Tel Aviv University.
3. Modeling program
The collected data is also analyzed using a computer program, which helps researchers estimate the otters’ population growth patterns.
4. Genetic diversity research
Another otters’ DNA research is conducted by the Hebrew University Faculty of Agriculture in
The data accumulated over years of surveys clearly indicate that the common otter population in Israel is at an increasing risk of extinction, a result of their habitats being destroyed and fragmented.
The habitats are diminishing and there is almost no regeneration evident at previously populated sites. This rare species’ survival depends on the combination between the quality of the habitats and a linkage between them.
What can we do?
Rehabilitate ecological corridors –the lack of linkage between different wetlands habitats is one of the biggest factors affecting the otters.The southern Jordan corridor is the main connection between the northern otter population (the Hula Valley and the Kinneret) and the southern population (Beit-She’an and west of the Kishon River).
The rehabilitation project planned for the southern Jordan River which focuses on improving the water quality and regenerating the river’s natural vegetation could prove to be a boon for the otter population, as has been seen in the northern Jordan which has already undergone rehabilitation. This is a highly encouraging manifestation of the benefits derived from ecological rehabilitation process.
Regenerate wetland habitats – as already evident in the Hula Valley,
the recovery of habitats has helped the otters. Other bodies of water such as abandoned fish ponds should be examined, and turned into sustainable habitats.
Prevent road-kill – unfortunately traffic accidents are a major cause of death for otters. Creating safe passages under roads dramatically lowers the incidence of animals being run over. All newly planned or reconstructed bridges should incorporate such passages.
Reintroduction - given the dwindling otter population habitat restoration may not be sufficient. An attempt to establish a breeding colony is currently underway in cooperation with the Jerusalem Biblical Zoo, using a local female and a Russian male. We hope that the offspring of this family can be introduced back into the wild in the future.
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